/*****************************************************************************
 *                                                                           *
 *  This file is part of the BeanShell Java Scripting distribution.          *
 *  Documentation and updates may be found at http://www.beanshell.org/      *
 *                                                                           *
 *  Sun Public License Notice:                                               *
 *                                                                           *
 *  The contents of this file are subject to the Sun Public License Version  *
 *  1.0 (the "License"); you may not use this file except in compliance with *
 *  the License. A copy of the License is available at http://www.sun.com    * 
 *                                                                           *
 *  The Original Code is BeanShell. The Initial Developer of the Original    *
 *  Code is Pat Niemeyer. Portions created by Pat Niemeyer are Copyright     *
 *  (C) 2000.  All Rights Reserved.                                          *
 *                                                                           *
 *  GNU Public License Notice:                                               *
 *                                                                           *
 *  Alternatively, the contents of this file may be used under the terms of  *
 *  the GNU Lesser General Public License (the "LGPL"), in which case the    *
 *  provisions of LGPL are applicable instead of those above. If you wish to *
 *  allow use of your version of this file only under the  terms of the LGPL *
 *  and not to allow others to use your version of this file under the SPL,  *
 *  indicate your decision by deleting the provisions above and replace      *
 *  them with the notice and other provisions required by the LGPL.  If you  *
 *  do not delete the provisions above, a recipient may use your version of  *
 *  this file under either the SPL or the LGPL.                              *
 *                                                                           *
 *  Patrick Niemeyer (pat@pat.net)                                           *
 *  Author of Learning Java, O'Reilly & Associates                           *
 *  http://www.pat.net/~pat/                                                 *
 *                                                                           *
 *****************************************************************************/


package bsh;

public final class BSHLiteral extends SimpleNode
{
	public static volatile boolean internStrings = true;

	public Object value;

	BSHLiteral(int id) { super(id); }

	public Object eval( CallStack callstack, Interpreter interpreter )
		throws EvalError
	{
		if ( value == null )
			throw new InterpreterError("Null in bsh literal: "+value);

		return value;
	}

	private char getEscapeChar(char ch)
	{
		switch(ch)
		{
			case 'b':
				ch = '\b';
				break;

			case 't':
				ch = '\t';
				break;

			case 'n':
				ch = '\n';
				break;

			case 'f':
				ch = '\f';
				break;

			case 'r':
				ch = '\r';
				break;

			// do nothing - ch already contains correct character
			case '"':
			case '\'':
			case '\\':
				break;
		}

		return ch;
	}

	public void charSetup(String str)
	{
		char ch = str.charAt(0);
		if(ch == '\\')
		{
			// get next character
			ch = str.charAt(1);

			if(Character.isDigit(ch))
				ch = (char)Integer.parseInt(str.substring(1), 8);
			else
				ch = getEscapeChar(ch);
		}

		value = new Primitive(new Character(ch).charValue());
	}

	void stringSetup(String str)
	{
		StringBuilder buffer = new StringBuilder();
		int len = str.length();
		for(int i = 0; i < len; i++)
		{
			char ch = str.charAt(i);
			if(ch == '\\')
			{
				// get next character
				ch = str.charAt(++i);

				if(Character.isDigit(ch))
				{
					int endPos = i;

					// check the next two characters
					int max = Math.min( i + 2, len - 1 );
					while(endPos < max)
					{
						if(Character.isDigit(str.charAt(endPos + 1)))
							endPos++;
						else
							break;
					}

					ch = (char)Integer.parseInt(str.substring(i, endPos + 1), 8);
					i = endPos;
				}
				else
					ch = getEscapeChar(ch);
			}

			buffer.append(ch);
		}

		String s = buffer.toString();
		if( internStrings )
			s = s.intern();
		value = s;
	}
}
